Am I being to sensitive or was this just rude?!

So Thursday afternoon I ran into my Brother and his wife at my daughter’s school conference. We talked and shared stories considering we are both pregnant 10 days apart to be exact. Well the day after I went on lunch break and opened my phone to a message from my sister in law saying exactly “ Are you sure your going to work up till you deliver you look pretty miserable.” Lemme tell you I was so offended and I actually cried in the restroom. Well for one it was a big day for me I had just gotten off work (I’m a daycare infant teacher which is harder than ppl expect imagine taking care of 8 babies all day) then I had to drive clear across town to get one of my daughters from day camp then shopping for dinner then finally her school conference. So yes I’m very tired at the point I saw her. But I felt so offended because she is a at home mother of one older aged child and have enough time to rest and look tip top shape. She was aware of my crazy day and tbh I would never tell a nine month pregnant woman that she looks miserable EVER! Especially after a long day of work etc. Side note: I felt completely fine and I can handle myself just perfectly at work was even clear by my Ob to continue working this is my third child so I’m well aware of what I can and cannot handle at this point of my pregnancy. I don’t know did she cross the line or am I being a big baby?